quest - 22-10-2009 at 15:45
Hi all,
I have granite marble in my kitchen and need to trim 2-5 m"m on one side (70 c"m length, 5 c"m width).
to trim it mechanically I need special tools with diamond saw.
So I thought maybe try to attack it with some strond acid.
Googling it gave me opposite opinions.
Which acids should work for this job? (and no HF of course)
maybe othe ideas?
thanks,
quest
kclo4 - 22-10-2009 at 16:27
I really don't think this is the best way to go about it, however I may be wrong.
Marble is often made out of calcium carbonate, granite marble probably is high in SiO2, and silicates, however.
If it is made mostly of calcium carbonate, an acid such as hydrochloric acid, acetic acid, and others that form soluble calcium salts should work.
Xenoid - 22-10-2009 at 16:28
What is "granite marble"!
You either have GRANITE - a siliceous coarse grained igneous rock, or MARBLE - metamorphosed limestone (CaCO3 - calcium carbonate). There is no such
thing as "granite marble".
Only hydrofluoric acid will dissolve granite - and I don't recommend that! 
Pretty much any acid will dissolve marble.
Quite frankly the acid idea is nuts!
I suggest you get a specialist with a diamond saw (concrete cutter?) to trim your granite, but don't forget it will need polishing, unless it's a back
edge - a big job!
A silicon carbide or similar blade in a circular saw would probably be OK for marble.
entropy51 - 22-10-2009 at 16:49
Well, obviously not HF. Much too messy.
A stream of F2 would make a much cleaner cut.
12AX7 - 22-10-2009 at 17:35
I bet a plasma cutter would do it. Got a metalworking friend? 'Course, it'll explode off chunks and slag like nobody's business.
CO2 laser is also a possibility. And abrasive waterjet. Neither tends to be a portable solution though, you'd have to remove and transport it to the
cutter. At that point you might as well call a professional installer.
Tim
Sedit - 22-10-2009 at 17:54
I know your more then likely looking for a chemical means but in order to remove only 2-5 mm then your best bet is an orbital sander with the proper
grit on it. It may take a bit but the efforts you would put into preventing the rest of the counter from getting messed up using acids would be no
childs play either
If its marble(white) you can attack that with ease using HCl but you will have an acid mist which will etch alot of the good counter top and you will
also be left with a very rough edge that needs sanding anyway. When installing these on yachts we would sand off with a DA sander sometimes more then
1/2 inch if the fit was not right.
If all else fails why not just go to a hardware store and see if you can rent a wet saw for the day. It may cost a bit more but the job it does will
look better.
Good luck and be careful because you do NOT want to crack that shit. Thats the reason we use to use a sander as opposed to the wet saw and we had both
right in our reach at all times. Slow and steady wins the race.
JohnWW - 22-10-2009 at 20:13
For either marble or granite, or a cement-based artificial stone for that matter, you could simply use a hand rotary power saw (made by firms like
Skil, Black & Decker, Bosch, Makita, etc.) fitted with a masonry cutoff disk. Such disks are made of abrasives like silicon carbide glued
together, reinforced by fibrous material like asbestos; but they wear down fairly fast, so you would need to bu several of them. Wear goggles,
ear-muffs, and an air filtering mask while using it.
I have fairly often done this, for cutting tiles, bricks, and small slabs of stone or concrete. For greater thicknesses of stone, and certainly more
than about 50 mm thick, you would need to hire or buy a bigger concrete-cutter, and keep the disk lubricated and cooled with water.
bquirky - 22-10-2009 at 20:23
It might be easer to move whatever is next to the granite by 2-5mm even if it involves chipping at some bricks. 